The probability of a resistor being defective is 0.02. There are 50 such resistors in a circuit

Q. The probability of a resistor being defective is 0.02. There are 50 such resistors in a circuit. The probability of two or more defective resistors in the circuit (round off to two decimal places) is     .

Solution:

Probability of a resistor being defective (P) = 0.02

Number of resistors (n) = 50

Mean (λ) = np = 50 × 0.02 = 1 Let x be the random variable which represents the number of defective resistors.

By using Poisson distribution, The probability of two (or) more defective resistors = P(X ≥ 2) = 1 – P (X = 0) – P (X = 1)